Ultrafast and Controllable Construction of Sb Particle-Loaded Bead-Like Carbon Nanofibers for Long Cycle-Life Sodium-Ion Storage

Abstract

Antimony (Sb) exhibits excellent conductivity and reactivity with sodium ions, which can be attributed to its distinctive puckered layer structure. Additionally, it has the potential to achieve a high theoretical capacity of 660 mAh g^–1 through the formation of Na₃Sb. However, the significant volume expansion (approximately 390%) that occurs during the charging process restricts its practical applications. To tackle these challenges, we developed a fast Joule heating technique to successfully ultrafast construct Sb nanoparticles into the bead-like structure of N,S-codoped asphalt-based carbon fibers (N/S-CNF). This unique bead-like structure effectively inhibits the volume expansion of the metal during the charging and discharging process. In addition, the 1D carbon nanofibers contribute to the formation of a robust electrode framework and enable fast electron transfer during cycling to facilitate the kinetics. These advantages together contribute to the excellent cycling stability and rate performance of self-supported Sb@N/S-CNF nanocomposites used as anode materials for sodium-ion batteries (SIBs). The specific capacity was still as high as 263.46 mAh g^–1 at 0.1 A g^–1after 150 cycles and 221.1 mAh g^–1 at 0.5 A g^–1 after 750 cycles with a capacity retention rate of 83.9%. These findings provide ideas for the ultrafast preparation of binder-free Na⁺ storage nanomaterials.